Lock release latch assembly for a collapsible chair having a fold-down back

ABSTRACT

A collapsible chair including a seat, a pair of arm rests at opposite sides of the seat, a rotatable fold-down back, and a lock release latch assembly that is manually accessible at the rear of the fold-down back. The lock release latch assembly has a rotatable latch that is connected by way of first and second locking cables to a pair of locking pins that extend from opposite sides of the fold-down back to be removably attached to respective ones of the pair of arm rests. A lifting force applied to the latch causes a corresponding pulling force to be applied to each of the pair of locking pins via the first and second locking cables, whereby the locking pins are withdrawn from the pair of arm rests. Accordingly, the fold-down back of the collapsible chair is rotatable from an upright position standing generally vertically upward relative to the seat to a generally horizontal folded position lying above the seat in face-to-face alignment therewith. With the fold-down back rotated to its folded position, the chair will have a compact, space-efficient configuration which is suitable for storage and/or transport without requiring that the chair be disassembled.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a lock release latch assembly including a latch that is accessible at the rear of a fold-down back of a collapsible home or office chair. Manipulating (i.e., rotating) the latch allows the fold-down back of the chair to be rotated from an upright position standing vertically above the seat of the chair during use to a folded position lying above the seat in face-to-face alignment therewith to facilitate a compact, space-efficient configuration suitable for storage or transport.

2. Background Art

Occasionally, it is necessary to transport or store one or more chairs of the kind having a seat, a back standing above the seat to support the user's back thereagainst, and a pair of arm rests located adjacent opposite sides of the seat. In those cases where a large number of chairs are to be shipped or stored, a correspondingly large amount of space will typically be required which increases both the shipping/storage costs and inefficiency. For example, where the chairs are to be shipped by boat and/or by truck, the cargo space available may be quickly consumed by a relatively few chairs. To overcome this problem, it is known to disassemble the chairs prior to shipment. However, such disassembly also mandates an additional assembly once the chairs reach their final destination. Consequently, time is wasted during both assembly and disassembly which contributes to the overall shipping costs that are ultimately passed through to the purchaser. Moreover, parts of the chair can become lost following disassembly which may prevent reassembly and, therefore, result in the chair being ultimately scrapped. In certain situations, assembly of the chair is left to the purchaser. In this case, some special skill and/or tools are often required before the chair is ready to use. If the purchaser is unable to easily complete the assembly in a reasonable time, frustration may occur which can result in the chair going unused or returned to the vendor.

Accordingly, it would be advantageous to have a collapsible chair which is capable of quickly and easily achieving a compact, space-efficient configuration suitable for storage and/or transport without having to first disassemble the chair and then reassemble the chair prior to use. In this regard, one example of a collapsible chair having a rotatable fold-down back is available by referring to U.S. Pat. No. 6,786,553 which issued to James E. Grove on Sep. 7, 2004.

SUMMARY OF THE INVENTION

Briefly, and in general terms, a lock release latch assembly is disclosed including a latch which is accessible at the rear of a rotatable a fold-down back of a collapsible home or office chair. The lock release latch is adapted to be manually manipulated (i.e., rotated) by the user to control the rotation of the fold-down back from an upright position standing vertically above the seat of the chair to a folded position lying above the seat in face-to-face alignment therewith. With the back rotated to its folded position, the chair will have a compact, space-efficient configuration which is suitable for storage and/or transport.

In a preferred embodiment, the latch of the lock release latch asssembly is surrounded by a latch housing that is received and retained within a housing cavity at the rear of a solid (e.g., plywood) back rest support located inside the fold-down back of the chair. The latch is pivotally coupled to the lock housing by means of a coupling pin such that the latch can rotate in response to a lifting force applied thereto between an at-rest position lying entirely inside the lock housing and a raised position extending outside the lock housing. A spring urges the lock release latch to automatically return from the raised position to its initial at-rest position when the lifting force is terminated.

A pair of locking pins are connected by respective locking cables to the latch of the lock release latch assembly. The locking pins are slidable through locking collars carried by side brackets that are located at opposite sides of the fold-down back of the chair. The locking collars of the side brackets are loaded with locking springs which push the locking pins outwardly from the sides of the fold-down back for receipt by locking holes formed in respective arm rests of the chair. With the pair of locking pins projecting outwardly from the sides of the fold-down back and captured in the locking holes formed in the arm rests and the lock release latch in its at-rest position, the fold-down back will be locked in the aforementioned upright position.

When it is desirable to fold the collapsible chair to a compact, space-efficient collapsed configuration, the user applies a lifting force to the lock release latch to cause the latch to rotate from its initial at-rest position to the raised position. The rotation of the lock release latch causes a corresponding pulling force to be exerted on the pair of locking cables which, in turn, causes the pair of locking pins to be withdrawn from the locking holes formed in the arm rests and slide inwardly through the locking collars of the side brackets, whereby the locking springs will be compressed. With the lock release latch in the raised position and the pair of locking pins withdrawn from the locking holes formed in the arm rests, the fold-down back can now be rotated from the upright position towards the seat to the aforementioned folded position. When the lifting force is removed from the lock release latch, the latch will automatically rotate back to its at-rest position, the locking springs will automatically expand, and the locking pins will be pushed by the expanding locking springs outwardly from the locking collars of the side brackets so as to be positioned for receipt by the locking holes in the arm rests.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view showing the lock release latch assembly of this invention to be accessible at the rear of a rotatable fold-down back of a collapsible chair by which to enable the fold-down back to be rotated between upright and folded positions;

FIG. 2 shows the lock release latch assembly of FIG. 1 attached to a rigid back rest support of the rotatable fold-down back of the collapsible chair;

FIG. 3 shows a detailed exploded view of the lock release latch assembly according to a preferred embodiment;

FIG. 4 shows the collapsible chair with the rotatable fold-down back thereof standing upwardly above the seat of the chair in the upright position;

FIG. 5 shows the collapsible chair after a lock release latch of the lock release latch assembly has been lifted and the rotatable fold-down back of the chair has been rotated from the upright position of FIG. 4 towards a folded position; and

FIG. 6 shows the collapsible chair with the rotatable fold-down back thereof in the folded position lying above and in face-to-face alignment with the seat of the chair to establish a compact, space-efficient chair configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The lock release latch assembly 1 according to a preferred embodiment of the present invention is initially described while referring to FIGS. 1-3 of the drawings. FIGS. 1 and 2 show the front of a solid (e.g., plywood) back rest support 3 to be carried inside a rotatable fold-down back of a collapsible home or office chair (designated 70 in FIGS. 4-6). A housing cavity 5 (best shown in FIG. 1) is formed through the back rest support 3 for receipt therewithin of the lock release latch assembly 1. As will be explained in greater detail hereinafter when referring to FIGS. 4-6, manual access is provided to the lock release latch assembly 1 through the upholstery of the fold-down back of the collapsible chair 70 within which the back rest support 3 is located so that a user can control the rotation of the fold-down back from an upright position to a folded position.

The back release latch assembly 1 (best shown in FIG. 3) includes a hollow latch housing 7 that is sized for receipt by the housing cavity 5 that is formed in the back rest support 3. In the assembled configuration of FIG. 2, a latch retention bracket 9 is affixed to the front of the back rest support 3 so as to extend across the housing cavity 5 and thereby prevent the latch housing 7 from being pushed outwardly therefrom.

The lock release latch assembly 1 of FIG. 3 also includes a latch 10 having a rocker arm 12 and a cylindrical coupling sleeve 14. The latch 10 and the rocker arm 12 thereof are sized to be received inside the latch housing 7 such that the cylindrical coupling sleeve 14 of latch 10 is axially aligned with a pair of pin holes (only one of which 16 being visible in FIG. 3) through latch housing 7. A coupling pin 18 is pushed through the pin holes 18 and the coupling sleeve 14 located therebetween, whereby the latch 10 will be pivotally coupled to the latch housing 7. At the same time that it is pushed towards the coupling sleeve 14, the coupling pin 18 is also pushed through the coiled body of a spring 20.

The latch 10 of latch assembly 1 is adapted to rotate in response to a lifting force applied thereto around the coupling pin 18 relative to the latch housing 7 from an initial at-rest position located inside the latch housing (best shown in FIG. 4) to a raised position extending outside the latch housing 7 (best shown in FIG. 5). The effect of rotating the latch 10 between the aforementioned at-rest and raised positions will be disclosed when referring to FIGS. 4-6.

When the latch 10 of latch assembly 1 is rotated to its raised position in response to the lifting force, the rocker arm 12 thereof will also rotate and ride over the hollow interior of the latch housing 7. During the rotation of the latch 10 and the rocker arm 12, the spring 20 will be compressed and store energy. When the lifting force applied to the latch 10 is removed, the spring 20 will expand and release its stored energy. The energy released by the expanding spring 20 will cause the latch 10 to automatically rotate around the coupling pin 18 from the raised position back to its initial at-rest position. Likewise, the rocker arm 12 of latch 10 will rotate in an opposite direction at the interior of latch housing 7.

A pair of locking cables 24 and 26 are connected between respective locking pins 28 and 30 attached to first ends of the locking cables and a common (e.g., metal) cable terminal 32 attached to the opposite ends. The relaxed locking cables 24 and 26 are held in place outstretched against the back rest support 3 by a pair of cable clips 27. The cable terminal 32 is located within a cable terminal aperture or port 34 that is formed in the rocker arm 12 of latch 10. With the cable terminal 32 mated to cable terminal port 34, a rotation of the rocker arm 12, when the latch 10 is rotated from its at-rest position to the raised position, will cause a corresponding pulling force to be applied to each of the pair of outstretched locking cables 24 and 26. The pulling force is transferred from the locking cables 24 and 26 to respective ones of the locking pins 28 and 30 attached thereto, whereby to cause a displacement of the locking pins 28 and 30 towards the rocker arm 12 of latch 10, the advantage of which will soon be explained.

FIG. 3 shows a pair of side brackets 36 and 38 that are mounted to opposite sides of the back rest support 3 (of FIGS. 1 and 2) within the fold-down back of the collapsible chair 70 shown in FIGS. 4-6 to which the lock release latch assembly 1 of this invention is applicable. Each of the side brackets 36 and 38 includes a hollow cylindrical locking collar 40 and 42. Locking collars 40 and 42 are sized for the slidable receipt therethrough of respective ones of the locking pins 28 and 30 attached to locking cables 24 and 26.

A screw-threaded locking plug 44 and 46 is rotated into engagement with each of the locking collars 40 and 42 of the side brackets 36 and 38 at a corresponding threaded portion (not shown) therein. A hole 48 and 50 extends longitudinally through each locking plug 44 and 46 to accommodate one of the locking cables 24 and 26. Located between each locking pin 28 and 30 and a stationary locking plug 44 and 46 is a coiled compression spring 52 and 54. It may be appreciated that a pair of cable runs are now established from the locking pins 28 and 30 to the cable terminal 32 at the rocker arm 12 of latch 10 through the coiled springs 52 and 54 and the holes 48 and 50 formed in locking plugs 44 and 46.

When the lock release latch assembly 1 has been installed, the locking pins 28 and 30 are initially positioned so as to extend outwardly and in opposite directions from respective ones of the locking collars 41 and 42 (best shown in FIG. 4). A pulling force applied to the locking cables 24 and 26 in response to a lifting force applied to and a corresponding rotation of the latch 10 will be transferred to the locking pins 28 and 30.

Accordingly, the locking pins 28 and 30 will be retracted inwardly through locking collars 40 and 42 (best shown in FIG. 5) and correspondingly pulled towards the stationary locking plugs 44 and 46. Inasmuch as the locking plugs 44 and 46 are fixedly attached inside the locking collars 40 and 42, the compression springs 52 and 54 will be compressed between the inwardly-moving locking pins 28 and 30 and the locking plugs 44 and 46.

As will be explained while referring to FIGS. 4-6, when the latch 10 of lock release latch assembly 1 is rotated by a user, the locking pins 28 and 30 will be retracted inwardly of the locking collars 40 and 42 of side brackets 36 and 38 so that the fold-down back of the collapsible chair 70 (of FIGS. 4-6) can be rotated from an upright position during use (best shown in FIG. 4) to a folded position lying above and in face-to-face alignment with the seat (best shown in FIG. 6). Once the fold-down back of the chair 70 has been rotated to its folded position, the lifting force applied by the user to the latch 10 of latch assembly 1 will cease and the pulling force applied to locking cables 24 and 26 will be terminated. At this time, the compression springs 52 and 54 will expand against the stationary locking plugs 44 and 46, whereby to drive the formerly-retracted locking pins 28 and 30 (of FIG. 4) through their respective locking collars 40 and 42 of side bracket 36 and 38 so that the locking pins 28 and 30 (of FIG. 6) are automatically returned to their initial position projecting outwardly from locking collars 40 and 42.

Each of the side brackets 36 and 38 also includes a pivot post 56 and 58 lying below locking collars 40 and 42. When the side brackets 36 and 38 are installed at opposite sides of the back rest support 3 of the fold-down back of the collapsible chair 70, the pivot posts 56 and 58 will project outwardly and in opposite directions to be pivotally coupled to respective arm rests of the chair. To this end, and as will now be explained, the pivot posts 56 and 58 of side brackets 36 and 38 establish pivot axes around which the fold-down chair back is rotatable between its aforementioned upright and folded positions.

Referring concurrently in this regard to FIGS. 3-6 of the drawings, there is shown (in FIGS. 4-6) a fully-upholstered collapsible chair 70 of the kind suitable for use in a home or office. The collapsible chair 70 is shown having a seat 72 to support the weight of a user, a pair of arm rests 74 and 75 located adjacent opposite sides of the seat 72 to support the user's arms, and rotatable fold-down back 76 to support the user's back thereagainst. The back rest support 3 (of FIGS. 1 and 2) which carries the lock release latch assembly 1 is located inside the upholstered fold-down back 76. By virtue of a user manipulating (i.e., rotating) the lock release latch assembly 1 disclosed while referring to FIGS. 1-3, the fold-down back 76 of the collapsible chair 70 is rotatable relative to the seat 72 and arm rests 74 and 75 from an upright position (of FIG. 4) standing vertically above the seat 72 during use to a generally horizontal folded position (of FIG. 6) lying above the seat in face-to-face alignment therewith to facilitate a compact, space-efficient configuration that is especially ideal for purposes of storage and transport.

The shapes of the seat 72, arm rests 74 and 75, and back 76 of the collapsible chair shown in FIGS. 4-6 are for purposes of illustration only and form no part of the present invention. In this same regard, the pair of arm rests 74 and 75 are shown, for example, connected to the collapsible chair 70 below the seat 72 thereof. The pair of arm rests 74 and 75 are also coupled to the chair 70 at the side brackets (designated 36 and 38 in FIG. 3) at opposite sides of the collapsible back 76.

More particularly, the pivot posts 56 and 58 (only one of which 56 being visible in FIGS. 4-6) which project from the side brackets 36 and 38 are mated to respective arm rests 74 and 75. As was previously disclosed, the pivot posts 56 and 58 establish pivot axes around which the fold-down back 76 can rotate between the aforementioned upright and folded positions. As was also previously disclosed, the locking pins 28 and 30 (only one of which 28 being visible in FIGS. 4-6) are slidably received through respective locking collars (designated 40 and 42 in FIG. 3) of the side brackets 36 and 38.

FIG. 4 shows the fold-down back 76 of the collapsible chair 70 in the upright position ready for use. In this case, the latch 10 of the lock release latch assembly 1 that is manually accessible within the latch housing 7 at the rear of the fold-down back 76 is in its normal at-rest position, and each of the locking cables 24 and 26 (of FIG. 3) which is attached to latch 10 is relaxed. Accordingly, each of the coiled compression springs 52 and 54 (of FIG. 3) is also relaxed and expanded, whereby the locking pins 28 and 30 are urged by springs 52 and 54 so as to extend outwardly from the locking collars 40 and 42 of side brackets 36 and 38. In the at-rest position of the latch 10, the outwardly-extending locking pins 28 and 30 are captured by respective locking recesses or holes (only one of which 78 being visible in FIGS. 4-6) that are formed in the arm rests 74 and 75. With the locking pins 28 and 30 captured by the locking holes (e.g., 78) that are formed in the arm rests (e.g., 74), the fold-down back 76 of collapsible chair 70 is locked in place and held in the upright position standing vertically above the seat 72. That is to say, the fold-down back 76 cannot be rotated around the pivot posts (e.g., 56) of the side brackets 36 and 38 in a direction towards the seat 72.

FIG. 5 shows the fold-down back 76 of the collapsible chair 70 rotated in a direction towards the folded position ready for storage or transport. In this case, a lifting force is applied to the latch 10 of the lock release latch assembly 1, whereby the latch 10 is rotated to the raised position extending outside the latch housing 7. As already described, the rotation of the latch 10 to the raised position causes a pulling force to be applied to each of the locking cables 24 and 26 (of FIG. 3). Accordingly, the locking pins 28 and 30 attached to locking cables 24 and 26 receive a corresponding pulling force by which to cause the locking pins (e.g., 28) to be pulled outwardly from the locking holes (e.g., 78) formed in the arm rests (e.g., 74) and retracted inwardly of the locking collars (e.g., 40). As the locking pins 28 and 30 slide inwardly through respective locking collars 40 and 42 of side brackets 36 and 38, the compression springs 52 and 54 that are sandwiched between the retracted locking pins 28 and 30 and the stationary locking plugs 44 and 46 will be compressed so as to store energy. As was also earlier described, such stored energy is necessary to cause the locking pins 28 and 30 to automatically slide outwardly from locking collars 40 and 42 when the lifting force applied to the latch 10 has ceased.

With the locking pins 28 and 30 withdrawn from the locking holes (e.g., 78) that are formed in the arm rests 74 and 75, the fold-down back 76 of collapsible chair 70 is now unlocked and free to be rotated around the pivot posts (e.g., 56) relative to the arm rests 74 and 75 to the collapsed position of FIG. 6 lying above and in face-to-face alignment with the seat 72. A locking pin guide ramp or channel (not shown), may be formed in each of the arm rests 74 and 75 so as to communicate with the locking holes 78 in the arm rests. The locking pins 28 and 30 ride through the locking pin guide channels to enable the locking pins 28 and 30 of FIG. 5 to move relative to the arm rests 74 and 75 when the locking pins are retracted from the locking holes 78 in the arm rests and the fold-down back 76 is rotated between the folded and upright positions. Reference may be made to U.S. Pat. No. 6,786,553 issued Sep. 7, 2004 for one example of a suitable locking pin guide channel which may be formed in the arm rests 74 and 75 of collapsible chair 70. 

1. A collapsible chair including a seat, a rotatable fold-down back, a pair of arm rests located at opposite sides of the seat, and a lock release latch assembly, said lock release latch assembly comprising: a latch having first and second latch positions; a locking projection extending from the rotatable fold-down back to be removably attached to a corresponding one of said pair of arm rests to lock the rotatable fold-down back in an upright position standing generally vertically above the seat; and a locking linkage extending between said latch and said locking projection, said latch having said first latch position at which said locking linkage is relaxed and said locking projection is attached to the one of said pair of arm rests for locking the rotatable fold-down back in said upright position, and said latch having said second latch position at which a pulling force is applied to said locking linkage for causing said locking projection to be removed from the one of said pair of arm rests for unlocking the rotatable fold-down back and thereby permitting said fold-down back to rotate towards the seat to a folded position.
 2. The collapsible chair recited in claim 1, wherein the latch of said lock release latch assembly is manually accessible at the rear of the rotatable fold-down back.
 3. The collapsible chair recited in claim 1, said chair also including a back rest support located within and surrounded by the rotatable fold-down back, said lock release latch assembly also comprising a latch housing carried by said back rest support, and said latch being mounted within said latch housing and movable therewithin between said first and second latch positions.
 4. The collapsible chair recited in claim 3, wherein said latch is pivotally mounted in said latch housing so as to rotate in response to a force applied thereto from said first latch position, at which said locking linkage is relaxed and said locking projection is attached to the one of said pair of arm rests, to said second latch position, at which a pulling force is applied to said locking linkage and said locking projection is removed from the one of said of pair of arm rests.
 5. The collapsible chair recited in claim 4, said lock release latch assembly also comprising a spring located in said latch housing, said spring being compressed to store energy when said latch rotates to said second latch position in response to said force applied thereto, said spring releasing the energy stored thereby and expanding so as to urge said spring to return to said first spring position when the force applied to said latch is terminated.
 6. The collapsible chair recited in claim 1, said lock release latch assembly also comprising a hollow locking collar located at one side of the rotatable fold-down back, said locking projection being removed from the one of said pair of arm rests and sliding through said hollow locking collar for unlocking the fold-down back when said latch has said second latch position and said pulling force is applied to said locking linkage extending between said latch and said locking pin.
 7. The collapsible chair recited in claim 6, said lock release latch assembly also comprising a pivot located at the one side of the rotatable fold-down back, said pivot extending from the one side of the fold-down back to the one of said pair of arm rests in order to establish a pivot axis around which the fold-down back rotates from said upright position towards the seat to said folded position when said latch has said second latch position and the fold-down back has been unlocked.
 8. The collapsible chair recited in claim 7, said lock release latch assembly also comprising a side bracket located at the one side of the rotatable fold-down back, each of said hollow locking collar and said pivot extending from said side bracket towards the one of said pair of arm rests.
 9. The collapsible chair recited in claim 6, said lock release latch assembly also comprising a spring located in said hollow locking collar, said spring being compressed within said hollow locking collar to store energy when said locking projection is removed from the one of said pair of arm rests so as to slide through said locking collar in response to said pulling force applied to said locking linkage when said latch has said second latch position, and said spring expanding and releasing the energy stored thereby for pushing said locking projection through said hollow locking collar and into attachment with the one of said pair of arm rests when the pulling force applied to said locking linkage is terminated.
 10. The collapsible chair recited in claim 9, said lock release latch assembly also comprising a stationary locking plug located within said hollow locking collar such that said spring lies between said locking projection and said stationary locking plug, said spring being compressed between said locking projection and said stationary locking plug in response to said pulling force applied to said locking linkage and the removal of said locking projection from the one of said pair of arm rests when said latch has said second latch position.
 11. A collapsible chair including a seat, a rotatable fold-down back, a pair of arm rests located at opposite sides of the seat, and a lock release latch assembly, said lock release latch assembly comprising: a latch having first and second latch positions; first and second locking pins projecting outwardly from first and opposite sides of the rotatable fold-down back to be removably attached to respective ones of said pair of arm rests in order to lock the rotatable fold-down back in an upright position standing generally vertically above the seat; and a first locking cable extending between said latch and said first locking pin and a second locking cable extending between said latch and said second locking pin, said latch having said first latch position at which said first and second locking cables are relaxed and said first and second locking pins are attached to the respective ones of said pair of arm rests for locking the rotatable fold-down back in said upright position, and said latch having said second latch position at which a pulling force is applied to each of said first and second locking cables for causing said first and second locking pins to be removed from the respective ones of said pair of arm rests for unlocking the rotatable fold-down back and thereby permitting said fold-down back to rotate towards the seat to a folded position.
 12. The collapsible chair recited in claim 11, said chair also including a back rest support located within and surrounded by the rotatable fold-down back, said lock release latch assembly also comprising a latch housing carried by said back rest support, and said latch being pivotally mounted within said latch housing and rotatable therewithin between said first and second latch positions, said latch being manually accessible at the rear of the rotatable fold-down back so as to receive a manually-applied force for causing said latch to rotate from said first latch position to said second latch position.
 13. The collapsible chair recited in claim 11, said lock release latch assembly also comprising first and second hollow locking collars located at the first and opposite sides of the rotatable fold-down back, said first and second locking pins being removed from the respective ones of said pair of arm rests and slidable through respective ones of said first and second locking collars for unlocking the rotable fold-down back when said latch has said second latch position and said pulling force is applied to each of said first and second locking cables extending between said latch and said first and second locking pins. 